This invention relates to markers for locating a splice within an endless loop of magnetic tape.
Endless loop magnetic tape cartridges are currently utilized by the broadcast industry for prerecorded voice messages such as commercials. This use necessarily includes locating the beginning of the prerecorded message and positioning it within the cartridge so that it can be played upon being cued without blank or silient space prior to the message, or without starting the playback in the midst of the message. Initially recording the message at a position right after the splice allows one to later locate the message by locating the splice. In addition, it is desirable to locate the splice and prevent the recording thereon since the gap between the ends of the tape within the splice adversely affects the recording and playing back of information across the splice. In the commercial broadcast area, the effect of the splice on record/playback quality is sufficiently troublesome that manufacturers have developed various techniques for locating the splice. The most common technique is to utilize optical means, e.g. placing a light-reflective substance on the tape's surface over the splice, illuminating the tape's surface, and using a photodetector to detect and signal the reflected light when the splice passes. With this technique consideration must also be given to ambient light conditions and the optical degradation of the light reflective substance. An alternate method employs mechanical means, e.g. detecting a variance in the thickness of the tape in the vicinity of the splice. This method is cumbersome especially when different tape thicknesses are used. Both of the above-described methods also require hardware in addition to that already present for the playback of the tape. This additional hardware and systems increase the cost and add complexity to the tape handling device.